In airplanes, it is useful, from within the cockpit, to be able to determine the pressure of tires on wheels in the landing gear.
For this purpose, it is known to mount a pressure sensor on the wheel rim, which sensor is suitable for measuring the inflation pressure of the tire mounted on the rim. The pressure sensor sends the value of the measurement it performs to an information processor unit placed on the fixed portion of the landing gear or inside the body of the airplane.
This makes it necessary to provide means for transmitting information between the moving and the fixed portions of the landing gear.
In particular, it is known to provide two concentric coils respectively on the hub of the wheel and on the spindle on which the hub is mounted to rotate, the coils together constituting a transformer. The coil carried by the hub is connected to the pressure sensor while the coil carried by the wheel spindle is connected to the information processor unit.
The signal delivered by the sensor to the coil carried by the hub and corresponding to the value of the pressure in the tire induces a signal in the coil carried by the spindle of the landing gear. This signal is analyzed by the information processor unit in order to deduce therefrom the pressure in the tire.
That solution operates in satisfactory manner. Nevertheless, the presence of two concentric coils makes the arrangement relatively bulky. Using a transformer to transmit information between two mutually rotary portions requires precautions to be taken concerning the electromagnetic environment.